The 900-year-old prophecy of St. Malachy that predicts Pope Francis, the 112th pontiff in a specific line, will be the last pope applies labels to each Catholic leader, many of which strikingly coordinate with each man's official coat of arms.

Malachy was a Catholic saint who lived in Ireland in the 12th century. His "Prophecy of the Popes," as it has come to be known, forecast that there would be 112 popes from that time until Jesus made His triumphant return to the planet. The sudden and unexpected resignation of Pope Benedict XVI was the spark igniting the new wildfire of speculation due to one simple reason: his successor, Pope Francis, is the end of the line.

In "The Last Pope?" several papal coats of arms are displayed as Cris Putnam, co-author of "Petrus Romanus: The Final Pope Is Here," explains how Malachy's descriptions fit in with specific design features.

Says Putnam of Pope Paul VI: "The prophecy for him is 'Flos Florum, Flower of Flowers.' Sounds pretty simple, kind of vague, right? When you look at his coat of arms, it has three fleurs-de-lis. This is a French monarchy symbol that means 'Flower of the Lily,' and that's really the whole coat of arms.

"My thinking was 'maybe he saw that coming, and he saw the Malachy prophecy and he picked his coat of arms to match it,' but I did some research. When you become a bishop you have to have your coat of arms in place, and if you look at the time lines of these guys' careers, most of them are bishops 30 years before they're even eligible to be pope. Minimum of 20 or so. So if you think about the sort of guesswork, you'd have to get really lucky to figure out how many popes are between you and your eligibility and when he would die, and it doesn't seem that possible to manipulate that way.

"[Malachy's] prophecy really stunningly seems to describe [Paul's] coat of arms when it says 'Flower of the Lily.'"

Coat of arms for Pope Paul VI

Emmet O'Regan is a historical blogger from Northern Ireland featured in the film. He explains that Malachy's motto for Pope Leo XIII, who served from 1878 to 1903, was Lumen in Coelo, which means "Light in the Sky." Leo's coat of arms includes a comet in the sky on the left side.

Coat of arms for Pope Leo XIII

Pope Gregory IX served in the 13th century. His Malachy motto was Auis Ostiensis, or Bird of Ostia. Gregory was cardinal bishop of Ostia, and his coat of arms includes an eagle, below.

So is Pope Francis indeed the "last pope"? The prophecy's moniker for his papacy is "Petrus Romanus," or "Peter the Roman."

In the documentary, Tom Horn, co-author of "Petrus Romanus," says he believes the motto fits just fine.

Explains Horn in the film: "We had given interviews [prior to the election of Pope Francis] saying it would be a mistake to try to nail down the last pope having the Christian name Peter, that in fact the only thing that it would take to fulfill the prophecy would be a cardinal of Italian descent. And low and behold Jorge Bergoglio, Italian descent, parents full-blooded Italians, or in the old language 'Romans.'

"But he names himself after Francis of Assisi. Now this is a Catholic friar who lived in the late 1100s and the early 1200s, but his name of birth Giovanni Di Pietro Di Bernardone, Peter. He was an Italian, or Roman in the old language, a man whose name can literally be translated as 'Peter the Roman.' So to take that as a namesake, well it was intriguing to say the least."